Speed control of electrically-propelled vehicles.



'No. 774,494. 1 PATENTED NOV; 8, 1904.

v n SI r I SPEED CONTROL OF ELECTRICALLY PROPELLED VEHICLES.

APPLICATION rlnnbmm a, 1903.

no MODEL. a sums-sum 1.

l/Vl/ENTOR J4 Sm/A RMJ/V ATTORNEYS.

PATENTED note. 1904-.

J. s. RAWORTH. SPEED CONTROL OF ELECTRIGALLY PROPBLLED VEHICLES.

APPLICATION FILED JUNE 5, 1903.

3 SHEETS-BHEET 2.

N0 MODEL.

M r 0 w a HR N w n 1 J.

' Arm/mus,

No. 774,494, M PATENTED NOV. 8, 1904. J. s. RAWORTH. SPEED CONTROL OF ELEGTRICALLY PROPBLLBD VEHICLES. APPLICATION FILED JUNE 5 1903.

N0 MODEL. I v 3SHEBTS-SHEET 3.

; I Mi i) M I Q N INVENTOR J54 Swizz RMJA ATTORNEYS.

UNTTED STATES Patented November 8, 1904.

JOHNSMITH RAWORTH, OF LONDON, ENGLAND.

SPEED CONTROL OF ELECTRlCALLY-PROPELLED VEHICLES- SPECIFICATION forming part of Letters Patent No. 774,494, dated November 8, 1904.

Application filed June 5, 1903.

T0 alt w/w'm, it may concern.-

Be it known that I, JOHN SMITH RAWORTH, V

two circuits, one a shunt field-circuit and the other an armature-circuit.

The object of the invention is to make the electromotive force of the armature to some extent independent of the current and of the direction of the current in the armature, and for this purpose the motors have on the fieldmagnet a shunt-winding. By this means it is possible to provide the armature with an abnormally strong field under certain conditions that is to say, when starting the vehicle from a state of rest and when retarding the motion of the moving mass.

In the accompanying drawings, Figures 1 and 2 illustrate diagrammatically the invention in its simplest form. Fig. 3 is a view of the interlocking plate. Figs. 4 and 5 illustrate diagrammatically a development of the invention shown in Figs. 1 and 2. Figs. 6 and 7 are views of the speed-lever. Figs. 8 and 9 illustrate diagrammatically a further development of the invention shown in Figs. 1 to 5.

(t represents pure shunt-wound motors having a fixed line of commutation and carbon brushes. 1

Z) represents the shunt field-windings, and their resistance is lower than is usual with ordinary sh unt-wound motors.

0 is a resistance that can be placed in or cut out, either partially or entirely, of circuit with the field-windings b. The amount of Serial No. 160,170. (No model.)

number of contact-blocks, one of which is connected directly to earth E and the others of which are each separately connected to a different part of the resistance 0. g and h are other contact-blocks that are dead. When the speed-lever (Z is moved over the contacts g 71, the strength of the field-exciting current is varied, and the circuit is broken when the speed-lever contacts are on the contacts 9 7b.

The speed-lever (Z has preferably a foreand-aft movement, and the contact-blocks it are so connected up with the resistance 0 that forward movement of the speed-lever (Z inserts resistance in the field-circuit and backward movement of the lever cuts resistance out of the said circuit. It will be seen that by varying the position of the speed-lever within certain limits the speed of the motors can either be increased or decreased and each position of the lever corresponds to a certain speed of the motor.

The armature-circuit of the motors is governed by a lever 7', hereinafter called the power-lever. This power-lever is controlled by the speed-lever in such wise that the armature-circuit can be closed or opened only when the speed-lever is in its most rearward position. The power-lever j is in the form of a bell-crank lever, one arm of which is formed as a slotted plate m, Fig. 3. The power-lever is pivoted at It to the casing f. The speed-lever cl has a pin 9 thereon, which works in the slots n 0 p in the plate m and controls the motion of the power-lever as will hereinafter appear. The power-lever j governs a switch which passes over contacts t and u, connected, respectively, with the armatures a and with earthE. The contact 16 is made up of a number of contact-blocks, one of which is connected directly to earth E and the others of which are each separately connected to earth through a resistance 8. t and u are other contact-blocks that are dead.

Assuming now that a vehicle propelled by shunt-motors and controlled by controllers of the kind described be at rest and that it be desired to put it in motion, the speed-lever contacts would be on the contacts g and 7t and the switch-contacts of the power-lever on the contacts t and a, and such levers would be maintained in such position by engagement of the pin q on the speed-lever (l with a notch '2' at the end of the slot 12 in the plate 711. To 1 release the speed-lever (Z, it is necessary to 9 slightly turn the power-lever j on its pivot Z: so as to put the pin (1 and slotp in line. The speed-lever can then be drawn back, and during such rearward motion resistance is gradually cut out of the shunt field-circuit. hen the pin q arrives opposite the end of the slot 0, the movement of the speed-lever is arrested and the contacts on the speed-lever are in i such a position that all of the resistance (1 has been cut out of the shunt field-circuit. The motor-fields are thus at maximum excitation. The power-lever j is now free to be moved, and it is turned on its pivot Z: so as to bring the slot at in line with the pin This movement of the power-lever causes its switch-contacts to move over the contacts ta and gradually cut resistance .5 out of the circuit. \Nhen the pin q and slot n are in line, all resistance a is cut out of the armature-circuit. As soon as the pin 1 and slot a are in line the speedlever (Z, which is locked during the movement of the power-levery', is released and can be pushed forward, so as to increase the resistance in the shunt field-circuit, and thereby increase the speed of the motors. This forward motion of the speed-lever (Z causes its pin to travel along the slot 11. and lock the power-lever j, so that the circuit controlled thereby cannot be opened. To stop the vehicle, the speed-lever (Z is pulled back so that the shunt-field is raised to a maximum and the pin q and slot 0 placed in line. This frees the power-lever j, which is caused to turn automatically on its pivot Z': and break the armature circuit, the resistance s all being placed in series therewith before the circuit is broken by the passage of the switch-contacts onto the contact-blocks Z a. The speed lever (Z as soon as the power-lever j has completed its movement and brought the slot in line with the pin 7 can be pushed forward to the position in which the pin 1 engages the notch 1*, the shunt field-circuit being broken when such position is attained.

The switch governed by the power-lever can be so arranged that after breaking both positive and negative connections-2'. (2., when its contacts are on the contact-blocks Z" w it will short-circuit the armatures through a special series winding of fewer turns than is the case with ordinary series motors. For this purpose, as is shown in Figs. 1 and i an additional pair of contacts t 1.4 are provided in the power part of the controller. The power-lever switch-contacts move onto these whenever the power-circuit is broken. One of the contacts-viz, u/ is connected, through 2, with one side of the armatures through the series windings e, and the other of the contacts-*viz at is connected with the other side of the armatures. To prevent the possibility of the armatures being shortcircuited through the series winding while the field is excited by the shunt-winding, the controller is provided with an electromagnetically-operated switch 1 in the short circuit. This switch is magnetized and held open by the shunt-field current. the windings of the switch being connected in series with this circuit at A. 15 is an automatic switch which disconnects the armatures from line or battery when they are short-eircuited. The motors when thus short-circuited act as an emergency braking arrangement. In some cases, however, the special series winding may be replaced by a resistance, in which case the electromagnetic switch 1 is dispensed with.

In descending hills and when stopping the vehicle the motors act as generators and return current to line or to the battery, and thus act as a brake. The braking action is also in operation when the motors are shorteircuited through the resistance and when short circuited through the special series winding as.

If it be desired to apply this regulating device to motors having series windings as well as shunt-windings, then the controller or regulator is arranged with two handles or levers partially connected together and with a spring or its equivalent between them, so arranged that when the handles are untouched the spring will force them into a position whereby a switch short-circuits the series coils and the upper surface of the guide traversed by the handles is cam-shaped, so that the short-circuit switch cannot be opened except when the shunt-field is very strong. Figs. & and 5 illustrate diagrammatically an arrangement for the purpose, and Figs. 6 and '7 are detail views of the speed-lever. w is the second lever that is carried by the speed-lever (Z and so arranged and controlled that normally the lever w is maintained in a position remote from the speed-lever (Z. This may conveniently be done by means of a spring :11. The second lever w controls, through a connector a switch y, which is caused to normally short-circuit the series coils "n, that are so wound as to augment the lields when the motors are acting as generators. The upper surface of the controller-casing fis so formed for a portion of its length 5 that a pin 6 on the second lever is in contact therewith, so as to prevent the lever w being moved to re move the short circuit on the series coils 0:. Such movement is, however, permitted to take place when the pin 6 is opposite a recessed part '7 of the controller-casing. This recessed part 7 is so placed and of such a length that the removal of the short circuit on the series winding can take place only when the fields are near their maximum excitation by the shunt-windings. In descending a hill the driver draws back the speed-lever (Z, so to decrease the resistance 0 in series with the shunt-windings b, and then the motors by such increase of field become generators and return current to the line; but if the retarding action caused by the generation of current be not suflicient to keep the vehicle in hand then the driver grasps the braking-handle w, so as to open the switch y and remove the short circuit on the series windings o and augment the fields.

Figs. 8 and 9 illustrate diagrammatically a combination of the two arrangements shown and described with reference to Figs. land 2 and 4 and 5. An additional resistance 3 is shown in this figure. This resistance spans the contacts of switch 1 and is cutout of circuit by the closing of the switch whenever the current through the shunt-windings b is interrupted. The operation of the parts shown in Figs. 8 and 9 will be understood from what has been said with respect to the arrangements hereinbefore described.

What I claim is- 1. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with a shunt field-Winding, of means for controlling the field-circuit, means for controlling the armature-circuit, and interlocking means so arranged that the armature-circuit cannot be. made or broken until the field-circuit-controlling means are in a certain position.

2. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with a shunt field-winding,-

trolling said armature-circuit, and means for interlocking said handle and armature-circuitcontrolling means and preventing the make or break of said armature-circuit until the motor shunt-field is at its strongest.

4. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with a shunt field-winding, of a shunt field-circuit, a resistance in said circuit, said resistance being capable of variation, a regulating-handle adapted to vary said resistance, an armature-circuit, a lever for controlling said armature-circuit and means for interlocking said handle and lever and preventing the make or break of said armaturecircuit until the motor shunt-field is at its strongest.

5. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with ashunt field-winding, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt fieldwinding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit and means for interlocking said handle and lever and preventing the make or break of said armature-circuit until the motor shunt-field is at its strongest.

6. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with a shunt field-winding, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt fieldwinding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a pin on said regulatinghandle adapted to engage with said lever and form an interlocking means therefor and prevent the make or break of said armature-circuit except when the field is at its strongest.

7. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with ashunt Field-winding, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt fieldwinding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a cam carried by said lever, a pin on said regulating-handle adapted to engage with said cam and lock the same, said lever and said armature-circuit closed or open.

8. In a regenerative motor-control system for electrically-propelledvehicles, the combination with motors with a shunt field-winding, of a shunt field-circuit, a regulating-handle therefor. a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-- for electrically-propelled vehicles, the combination with motors with a shunt field-winding, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt fieldwinding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a cam carried by said lever, a pin on said regulating-handle adapted to engage with said cam and prevent movement of the said lever except when the motor shunt-field is at its strongest.

10. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors with a shunt field-winding, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt fieldwinding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a slotted cam carried by said lever, a pin on said regulating-handle adapted to engage with the slots in said cam and prevent movement of said lever except when the motor shunt-iield is at its strongest.

11. In aregenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and se ries field-windings, of means for controlling said shunt field-circuit, means for controlling said series field-circuit, means for controlling the armature-circuit, and interlocking means so arranged that the armature-circuit cannot be made or broken, until the slmnt-iield-circuit-controlling means are in a certain position.

12. In aregenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and se ries field-windings, of means for controlling said shunt field-circuit, means for controlling said series field-circuit, means for controlling the armature-circuit, and means for interlocking the armature-circuit and shunt-field-controlling means, said series field-circuit being normally short-circuited and adapted to be placed in circuit and augment the iield When the motor is returning current to line.

13. In a regenerative motor-control system for electrieally-propelled vehicles, the combination with motors having both shunt and series field-windings, said series winding being normally short-circuited, of a shunt field-circuit, a variable resistance in said circuit, means for varying the resistance in circuit, means for controlling the armature-cireuit, and interlocking means so arranged that the armature-circuit cannot be made or broken until the field is at its strongest, and means for removing the short circuit on said series winding and augmenting the field when the motor is returning current to line.

14.. In a regenerative motor-control system for electricallypropelled vehicles, the combination with motors having both shunt and series [ield\\'indings, said series winding being normally short-circuited, of a shunt field-circuit, a resistance in said circuit, said resistance being capable of variation, a regulatinghandlc adapted to vary said resistance, an armature-circuit, means for controlling said armature-circuit, means for interlocking said handleand armature-cireuit-controllingmeans and preventing alteration to said circuit until the .shuntlield is at its strongest, and means for removing the short circuit on said series winding and placing said winding in circuit to augment the held when themotor is returning current to line.

15. In a regenerative motor-control system for eleetrically-propelled vehicles, the combination with motors having both shunt and series lield-windings, said series winding being normally short-circuited, of a shunt field-circuit, a resistance in said circuit, said resist ance being capable of variation, a regulatinghandle adapted to vary said resistance, an arnmture-circuit, a lever for controlling said armature-circuit, means for interlocking said handle and lever and preventing alteration of said armature-circuit until the shunt-field is at its strongest, and means for removing the short circuit on said series winding and plac ing said winding in circuit to augment the lield when the motor is returning current to line.

16. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and se ries field-windings, said series winding being normally short-circuited, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-winding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, means for interlocking said handle and lever and preventing alteration of said armaturecircuit until the shunt-field is at its strongest, and means for removing the short circuit on said series winding and placing said winding in circuit to augment the hold when the motor is returning current to line.

17. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having bothshunt and series field-windings, said series winding being normally short-circuited, of a shunt iield-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-winding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a gin on said regulating-handle adapted to engage with said lever and form an interlocking means therefor and prevent the make or break of said armature circuit except when the shunt-field is at its strongest, and means for removing the short circuit on said series winding and placing said winding in circuit to augment the field when the motor is returning current to line.

18. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and series field-windings, said series Winding being normally short-circuited, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-winding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a cam carried by said lever, a pin on said regulatinghandle adapted to engage with said cam and lock the same, said lever and said armaturecircuit closed or open, and means for removing the short circuit on said series winding and placing said winding in circuit to augment the field When the motor is returning current to line.

19. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and series field-windings, said series winding being normally short-circuited, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-winding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a slotted cam carried by said lever, a pin on said regulating-handle adapted to engage with one of the slots in said cam and lock the said armature-circuit closed or open, and means for removing the short circuit on said series Winding and placing said winding in circuit to augment the field when the motor is returning current to line.

20. In a regenerative motor-control system for electrically-propel]ed vehicles, the combination with motors having both shunt and series field-windings, said series Winding being normally short-circuited, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-winding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a cam carried by said lever, a pin on said regulating-handle adapted to engage With said cam and prevent movement of the said lever except when the motor-field is at its strongest, and means for removing the short circuit on said series winding and placing said winding in circuit to augment the field when the motor is returning current to line.

21. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and series field-windings, said series winding being normally short-circuited, of a shunt field-circuit, a regulating-handle therefor, a variable resistance in said circuit, contact-blocks connected to the several sections of said resistance and to the shunt field-Winding and adapted to be moved over by said handle to vary the resistance in circuit, an armature-circuit, a lever for controlling said armature-circuit, a slotted cam carried by said lever, a pin on said regulating-handle adapted to engage with the slots in said cam and prevent movement of said lever except when the motor shuntfield is at its strongest, and means for removing the short circuit on said series Winding and placing said winding in circuit to augment the field when the motor is returning current to line.

22. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and series field-windings, of a regulating-handle for controlling said shunt field-circuit, an armature-circuit, a lever for controlling the armature-circuit, a braking-handle carried by said regulating-handle and adapted to normally short-circuit the'series winding, as set forth.

23. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and series field-windings, of a regulating-handle for controlling said shunt field-circuit, an armature-circuit, a lever for controlling the armature-circuit, a braking-handle carried by said regulating-handle, a switch connected to said braking-handle adapted to control the series field-Winding and aspring connecting said handles and adapted to maintain said switch closed.

24. In a regenerative motor-control system for electrically-propelled vehicles, the combination With motors having both shunt and series field-windings, said series winding being normally short-circuited, of means for controlling said shunt field-Winding, means for removing the short circuit on said series lieldcircuit, means for controlling the armaturecircuit and means for interlocking said shuntfield and armature-circuit controlling means, a circuit connecting one side of said motors with the earth side of said series winding, a normally open switch in said circuit, said switch being adapted to be closed automatically and short-circuit the motors on themselves when the shunt-ficld and armaturecir cuitsare open.

25. In a regenerative motor-control system for electrically-propelled vehicles, the combination with motors having both shunt and series field-windings, said series winding being normally short-cireuited, of means for controlling said shunt field-winding, means for removing the short circuit on said series fieldcircuit, means for controlling the armaturecircuit and means for interlocking said shunt field and arnmture-circuit controlling means, a circuit connecting one side of said motors with the earth side of said series winding, an eleetromagnetically-operated and open switch in said circuit, said switch being adapted to he closed automatically and short-circuit the motors on themselves when the shunt-lield and armature-circuits are open.

26. In a regenerative motor-control system for electrically-propelled vehicles, the combi nation with motors having both shunt and series field-windings, said series winding being normally short-circuited, of means for con- JOHN SMITH. RAW'ORTH. \Vitnesses:

JOHN I. HALL, JNo. S. Bowman. 

